// 测试类
public class CourseSystemTest {
    public static void main(String[] args) {
        // 1. 创建课程对象
        Course java = new Course("C001", "Java程序设计");
        Course db = new Course("C002", "数据库原理");

        // 2. 测试学生类（含退课功能）
        Student student = new Student("S001", "张三");
        student.selectCourse(java);
        student.selectCourse(db);
        student.printWorksheet(); // 打印选课列表

        // 新增：测试退课
        student.dropCourse(db);
        System.out.println("退课后的选课列表：");
        student.printWorksheet();

        System.out.println("------------------------");

        // 3. 测试教师类
        Teacher teacher = new Teacher("T001", "李老师");
        teacher.addTaughtCourse(java);
        teacher.printWorksheet();
    }
}